.\"
.\" libdivecomputer
.\"
.\" Copyright (C) 2017 Kristaps Dzonsons <kristaps@bsd.lv>
.\"
.\" This library is free software; you can redistribute it and/or
.\" modify it under the terms of the GNU Lesser General Public
.\" License as published by the Free Software Foundation; either
.\" version 2.1 of the License, or (at your option) any later version.
.\"
.\" This library is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
.\" Lesser General Public License for more details.
.\"
.\" You should have received a copy of the GNU Lesser General Public
.\" License along with this library; if not, write to the Free Software
.\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
.\" MA 02110-1301 USA
.\"
.Dd January 5, 2017
.Dt DC_DEVICE_SET_FINGERPRINT 3
.Os
.Sh NAME
.Nm dc_device_set_fingerprint
.Nd set the last-seen dive fingerprint
.Sh LIBRARY
.Lb libdivecomputer
.Sh SYNOPSIS
.In libdivecomputer/device.h
.Ft dc_status_t
.Fo dc_device_set_fingerprint
.Fa "dc_device_t *device"
.Fa "const unsigned char data[]"
.Fa "unsigned int size"
.Fc
.Sh DESCRIPTION
Sets the last-seen dive fingerprint on a device opened with
.Xr dc_device_open 3 .
This mechanism is used to only download dives
.Dq newer
.Po
as reported by the dive computer, not necessarily on the calendar
.Pc
than the last seen dive.
.Pp
In general usage, the fingerprint is acquired (and saved) from the first
dive downloaded from a dive computer by
.Xr dc_device_foreach 3 .
In subsequent openings of the device, the fingerprint is set with
.Nm
and, when a dive reports a fingerprint matching that dive, the download
exits before reporting that dive.
.Pq The first fingerprint is saved again for subsequent invocations.
In this way, only the newest dives are reported.
.Sh RETURN VALUES
This returns
.Dv DC_STATUS_SUCCESS
if the fingerprint was set or one of several error values on error.
.Sh SEE ALSO
.Xr dc_device_open 3
.Sh AUTHORS
The
.Lb libdivecomputer
library was written by
.An Jef Driesen ,
.Mt jef@libdivecomputer.org .
The manpages were written by
.An Kristaps Dzonsons ,
.Mt kristaps@bsd.lv .
